Sensor device and steering wheel

ABSTRACT

A capacitive sensor device for use with a steering wheel is provided. The steering wheel includes a rim and a spoke that is connected to the inner side of the rim, and the sensor device is provided on the spoke. The sensor device includes an electrode configured to be capacitively coupleable to an object to be detected, and includes a controller configured to detect a change in capacitance of the electrode, and determine whether the object is in proximity to the rim or the spoke based on the change in the capacitance of the electrode. The change in the capacitance occurs in response to the object being in proximity to the rim or the spoke.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/JP2020/008999, filed on Mar. 3, 2020 and designating the U.S., whichclaims priority to Japanese Patent Application No. 2019-057316, filed onMar. 25, 2019. The contents of these applications are incorporatedherein by reference in their entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The disclosures herein relate to a sensor device and a steering wheel.

2. Description of the Related Art

When a driver drives a vehicle such as an automobile, the driver canchange the driving direction of the vehicle by turning a steering wheelwhile holding the steering wheel. The steering wheel is also referred toas a driving wheel.

Such a steering wheel may include a sensor device configured to detectwhether a driver is holding the steering wheel. Specifically, anelectrode (such as a capacitive sensor), configured to detect whether adriver is holding the rim of the steering wheel, may be provided insidethe rim of the steering wheel. In addition, a heater may also beprovided inside the rim of the steering wheel such that the driver doesnot feel cold when the driver's hand contacts or is placed in proximityto the steering wheel. However, if the heater is provided inside the rimof the steering wheel, the detection accuracy of the sensor device maybe decreased due to external influences such as an electromagnetic fieldformed around the heater and a change in detection sensitivityassociated with a temperature change.

RELATED-ART DOCUMENTS Patent Documents

-   Patent Document 1: Japanese Laid-Open Patent Publication No.    2015-147531

SUMMARY OF THE INVENTION

It is desirable to provide a sensor device that can detect whether aperson's hand contacts or is in proximity to a steering wheel with highaccuracy.

According to at least one embodiment, a capacitive sensor device for usewith a steering wheel is provided. The steering wheel includes a rim anda spoke that is connected to the inner side of the rim, and the sensordevice is provided on the spoke. The sensor device includes an electrodeconfigured to be capacitively coupleable to an object to be detected,and includes a controller configured to detect a change in capacitanceof the electrode, and determine whether the object is in proximity tothe rim or the spoke based on the change in the capacitance of theelectrode. The change in the capacitance occurs in response to theobject being in proximity to the rim or the spoke.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and further features of the present invention will beapparent from the following detailed description when read inconjunction with the accompanying drawings, in which:

FIG. 1 is a diagram illustrating a related-art steering wheel;

FIG. 2 is a cross-sectional view of a related-art steering wheel inwhich a heater is provided around a capacitive sensor;

FIG. 3 is a cross-sectional view of a related-art steering wheel inwhich a capacitive sensor is provided around a heater;

FIG. 4 is a perspective view of a steering wheel according to a firstembodiment;

FIG. 5 is a diagram illustrating detection areas of a steering wheelsensor according to the first embodiment;

FIG. 6 is a diagram illustrating a partially exploded perspective viewof the steering wheel sensor according to the first embodiment;

FIG. 7 is a block diagram illustrating the steering wheel sensoraccording to the first embodiment;

FIG. 8 is a diagram illustrating detection areas of a steering wheelsensor according to a second embodiment; and

FIG. 9 is a block diagram illustrating the steering wheel sensoraccording to the second embodiment.

DESCRIPTION OF THE EMBODIMENTS

According to at least one embodiment, a sensor device can detect, withhigh accuracy, whether a person's hand contacts or is in proximity to arim or a spoke of a steering wheel in conditions in which a capacitivesensor is unable to be provided inside the rim.

In the following, embodiments of the present invention will bedescribed. The same elements are denoted by the same reference numerals,and the description of the same elements will not be repeated.

(Description of Related-Art Steering Wheels)

First, related-art steering wheels will be described with reference toFIG. 1 through FIG. 3.

As illustrated in FIG. 1, a steering wheel used in a vehicle typicallyincludes an annular rim 10 and a spoke 20. The spoke 20 is connected tothe inner side of the rim 10 and is also connected to a steering column(not illustrated). Typically, when a driver drives a vehicle, the driveroperates or turns the steering wheel while holding the rim 10 with thehands. In the automobile market, self-driving vehicles have beenintroduced in recent years. However, because a self-driving function isconsidered to be a driving support function, even if a vehicle has aself-driving function, the driver is still required by law to placetheir hands on the steering wheel while driving. In light of this, it ispreferable for self-driving vehicles to have a function to determinewhether a driver's hand is placed at a position where the driver canimmediately operate the steering wheel, and alert the driver in responseto determining that the driver's hand is not placed at a position wherethe driver can immediately operate the steering wheel. For example, asteering wheel including a capacitive sensor inside a rim 10 is devisedso as to determine whether one or both of a driver's hands are holdingthe steering wheel.

Further, vehicles may be used in cold regions. In such a case, if asteering wheel is excessively colder than the body temperature of adriver, the driver would feel cold when the driver contacts the steeringwheel with the hands. As a result, it may be difficult for the driver totouch the steering wheel for a long period of time, and the driver'sdriving may be hindered. For this reason, the steering wheel may includea heater inside a rim 10 so as to heat and warm the rim 10 of thesteering wheel while the driver is driving the vehicle. Examples of theheater include a heating element that generates heat by causing acurrent to flow through a heating wire or the like. The heating elementis an element that generates heat through the resistance, and may beformed of a metallic material, such as nichrome, having a relativelyhigh resistance.

Accordingly, in the above case, the steering wheel may include both theheater and the sensor, such as a capacitive sensor, inside the rim 10.If the heater is provided inside the rim 10 of the steering wheel, theheater is preferably provided in a part of the rim 10 that is likely tobe held by the driver, which may be different from person to person.Similarly, if the sensor such as a capacitive sensor is provided insidethe rim 10 of the steering wheel, the sensor is preferably provided in apart of the rim 10 that is likely to be held by the driver, which may bedifferent from person to person.

In view of the above, both the heater and the sensor such as acapacitive sensor may be disposed around the circumference of the rim10, and one of the heater and the sensor is disposed inward relative tothe other. Specific examples will be described with reference to across-sectional view of a steering wheel in which a heater is providedaround a capacitive sensor as illustrated in FIG. 2, and across-sectional view of a steering wheel in which a capacitive sensor isprovided around a heater as illustrated in FIG. 3.

For example, in the steering wheel as illustrated in FIG. 2, acapacitive sensor 30 is provided around a core metal 11 that forms thecenter portion of a rim 10 of the steering wheel. A heater 40 isprovided around the capacitive sensor 30, and an outer skin 50 isprovided around the heater 40. With this configuration, when a driver'shand contacts or is in proximity to the rim 10 of the steering wheel,the capacitance of the capacitive sensor 30 changes. A controller (notillustrated) that is electrically connected to the capacitive sensor 30detects the amount of change in the capacitance, generates a detectionsignal, and determines whether the driver's hand contacts or is inproximity to the rim 10 of the steering wheel by comparing the detectionsignal to a predetermined threshold. However, in the example illustratedin FIG. 2, the heater 40 composed of a resistor made of an electricallyconductive metal is disposed adjacent to the capacitive sensor 30.Typically, the electrically conductive metal has a large capacitance,and thus, the heater has a large capacitance. Therefore, as compared towhen there is no influence of the heater 40, if the heater 40 isdisposed adjacent to the capacitive sensor 30, a change in thecapacitance of the capacitive sensor 30 would be affected by the heater40. As a result, the magnitude of a detection signal generated by thecontroller based on the change in the capacitance of the capacitivesensor 30 would change due to the influence of the heater 40, thuscausing the controller to fail to make an accurate determination.Further, a temperature change may cause a change in the capacitance ofthe capacitive sensor 30. Therefore, if heat from the heater 40 warmsthe capacitive sensor 30, the magnitude of a detection signal, generatedby the controller based on a change in the capacitance of the capacitivesensor 30, would change before and after the capacitive sensor 30 iswarmed. Therefore, the controller would be unable to make an accuratedetermination based on the detection signal.

Further, in the steering wheel as illustrated in FIG. 3, a heater 40 isprovided around a core metal 11 that forms the center portion of a rim10 of the steering wheel. A capacitive sensor 30 is provided around theheater 40, and an outer skin 50 is provided around the capacitive sensor30. With this configuration, heat generated by the heater 40 warms theouter skin 50 via the capacitive sensor 30, and is transferred to thedriver's hands. Thus, as compared to the configuration illustrated inFIG. 2, it would take time to warm the rim 10, and power consumed by theheater 40 would also increase.

Further, similar to the configuration illustrated in FIG. 2, in theconfiguration illustrated in FIG. 3, the electrically conductive heater40 is disposed adjacent to the capacitive sensor 30. Therefore, themagnitude of a detection signal, generated based on a change in thecapacitance of the capacitive sensor 30, would become unstable, thusmaking it difficult for the controller to make an accurate determinationbased on the detection signal. Further, similar to the configurationillustrated in FIG. 2, in the configuration illustrated in FIG. 3, ifheat generated by the heater 40 warms the capacitive sensor 30, themagnitude of a detection signal, generated based on a change in thecapacitance of the capacitive sensor 30, would change before and afterthe capacitive sensor 30 is warmed. Therefore, it would be difficult forthe controller to make an accurate determination based on the detectionsignal.

As described above, if the capacitive sensor 30 is provided inside therim 10 in the steering wheel, it may be difficult to accuratelydetermine whether the driver's hand contacts the steering wheel.

(Steering Wheel Sensor and Steering Wheel According to First Embodiment)

Next, a steering wheel sensor 102 (corresponding to a “sensor device”recited in the claims) according to a first embodiment and a steeringwheel 100 (corresponding to a “steering wheel” recited in the claims)will be described with reference to FIG. 4 through FIG. 7. Asillustrated in FIG. 4, the steering wheel 100 according to the firstembodiment includes a rim 110, a spoke 120, and a steering wheel sensor102 provided on the spoke 120. The spoke 120 is connected to the innerside of the rim 110 and is also connected to a steering column (notillustrated). The steering wheel sensor 102 includes a capacitive sensor130 (corresponding to an “electrode” recited in the claims) and acontroller 160 (corresponding to a “controller” recited in the claims).The capacitive sensor 130 can be capacitively coupled to an object(hereinafter referred to as an “operation body”) to be detected andhaving a capacitance. In the first embodiment, the capacitive sensor 130is provided along edge portions 121 a, 121 b, and 121 c, facing theinner peripheral surface of the rim 110, of the spoke 120. A heater 140configured to heat and warm the rim 110 is provided inside the rim 110.That is, the capacitive sensor 130 and the heater 140 are provided atdifferent positions of the steering wheel 100.

As illustrated in FIG. 7, the controller 160 is electrically connectedto the capacitive sensor 130.

In the first embodiment, the controller 160 generates a detection signalbased on a change in the capacitance of the capacitive sensor 130, andfurther performs a coding process on the detection signal so as tofacilitate the transmission of the detection signal. The controller 160communicates with an external device illustrated in FIG. 7 and transmitsthe detection signal to the external device. The external devicedetermines whether a driver's hand is placed at a position where thedriver can immediately operate the steering wheel by comparing thedetection signal to a predetermined threshold, and alerts the driver ifthe driver's hand is not placed at a position where the driver canimmediately operate the steering wheel.

Note that the controller 160 may determine whether the driver's hand isplaced at a position where the driver can immediately operate thesteering wheel.

Accordingly, in the steering wheel 100, because the capacitive sensor130 is provided away from the heater 140, the possibility that a changein the capacitance of the capacitive sensor 130 is affected by thecapacitance of the heater 140 is virtually eliminated. Further, thepossibility that a detection signal, generated by the controller 160based on the change in the capacitance of the capacitive sensor 130, isaffected by the capacitance of the heater 140 is virtually eliminated.Further, because the possibility that heat from the heater 140 istransferred to the capacitive sensor 130 is virtually eliminated, thecontroller 160 can accurately detect whether the driver's hand contactsor is in proximity to the steering wheel without being affected by theheater 140. Further, the heater 140 can efficiently warn the rim 10without being affected by the heat capacity of the capacitive sensor130.

Note that, while the controller 160 can detect whether the operationbody having a capacitance, such as the driver's hand, contacts or is inproximity to the steering wheel based on a change in the capacitance ofthe capacitive sensor 130, the value of the capacitance of thecapacitive sensor 130 depends on the distance between the capacitivesensor 130 and the operation body to be detected. As the operation bodyapproaches the capacitive sensor 130, the value of the capacitance ofthe capacitive sensor 130 increases, and as the operation body movesaway from the capacitive sensor 130, the value of the capacitance of thecapacitive sensor 130 decreases. By utilizing the above, the controller160 can adjust a detection area by adjusting a threshold or by using aplurality of thresholds to be compared to a detection signal generatedbased on a change in the capacitance of the capacitive sensor 130. Forexample, as illustrated in FIG. 4, even if the operation body is locatedin an area furthest from the rim 110, the controller 160 can determinewhether the operation body is in proximity to the rim 110 based on achange in the capacitance of a portion (such as 130 a or 130 b) of thecapacitive sensor 130. Specifically, as illustrated in FIG. 5, thecontroller 160 can determine whether the operation body is located inany of detection areas 150 a, 150 b, and 150 c, which are set in thesurroundings of the rim 110 and between the rim 110 and the edgeportions 121 a, 121 b, and 121 c, facing the inner peripheral surface ofthe rim 110, of the spoke 120.

In the first embodiment, the capacitive sensor 130 is included in thesteering wheel sensor 102. The driver side of the steering wheel sensor102 is covered by an exterior panel 125 illustrated in FIG. 5. Thecapacitive sensor 130 is formed of an electrical conductor such as oneline-shaped conductive wire, and is provided along the edge portions ofthe spoke 120. As illustrated in FIG. 5, the detection areas 150 a, 150b, and 150 c extend along a plane that includes the rim 110.

Further, the above-described rim 110 and the spoke 120 are connected byconnecting portions. Specifically, as illustrated in FIG. 4, connectingportions 120 a, 120 b, and 120 c connect the spoke 120 to the inner sideof the rim 110. A space is formed between the rim 110 and a part,extending from the connecting portion 120 a to the connecting portion120 b, of the spoke 120. Similarly, a space is formed between the rim110 and a part, extending from the connecting portion 120 a to theconnecting portion 120 c, of the spoke 120. Similarly, a space is formedbetween the rim 110 and a part, extending from the connecting portion120 b to the connecting portion 120 c, of the spoke 120.

The capacitive sensor 130 of the steering wheel sensor 102 includes asensor portion 130 a (corresponding to a “fragment” recited in theclaims). The sensor portion 130 a is provided along the edge portion 121a, facing the rim 110, of the spoke 120. The capacitive sensor 130further includes a sensor portion 130 b (corresponding to a “fragment”recited in the claims) provided along the edge portion 121 b, facing therim 110, of the spoke 120. The capacitive sensor 130 further includessensor portions 130 c and 130 d (corresponding to “fragments” recited inthe claims). The sensor portions 130 c and 130 d are provided alongparts of the edge portion 121 c, facing the rim 110, of the spoke 120.The capacitive sensor 130 further includes a sensor portion 130 e(corresponding to a “fragment” recited in the claims), a sensor portion130 f (corresponding to a “fragment” recited in the claims), and asensor portion 130 g (corresponding to a “fragment” recited in theclaims). The sensor portion 130 e is provided along the connectingportion 120 a, connecting the spoke 120 to the rim 110, the sensorportion 130 f is provided along the connecting portion 120 b, and thesensor portion 130 g is provided along the connecting portion 120 c.

As described above, the sensor portion 130 e (“fragment”) of thecapacitive sensor 130 is provided along the connecting portion 120 a,connecting the spoke 120 to the rim 110, the sensor portion 130 f(“fragment”) of the capacitive sensor 130 is provided along theconnecting portion 120 b, and the sensor portion 130 g (“fragment”) ofthe capacitive sensor 130 is provided along the connecting portion 120c.

As illustrated in FIG. 6, the capacitive sensor 130 is formed of oneconductive wire. The capacitive sensor 130 includes the sensor portion130 c, the sensor portion 130 f, the sensor portion 130 a, the sensorportion 130 e, the sensor portion 130 b, the sensor portion 130 g, andthe sensor portion 130 d, which are connected in this order. In thefirst embodiment, the capacitive sensor 130 may be formed of twoconductive wires. For example, the capacitive sensor 130 may be formedof a conductive wire that includes a part of the sensor portion 130 e,the sensor portion 130 a, the sensor portion 130 f, the sensor portion130 c, and formed of a conductive wire that includes the other part ofthe sensor portion 130 e, the sensor portion 130 b, the sensor portion130 g, and the sensor portion 130 d.

That is, the outer periphery of the spoke 120 includes the edge portions(121 a, 121 b, and 121 c) and the connecting portions (120 a, 120 b, and120 c), and the capacitive sensor 130 extends continuously along theouter periphery of the spoke 120.

In a configuration according to the first embodiment, it is assumed thatthe driver mainly holds lower portions 110 a and 110 b of the rim 110while the driver is driving the vehicle. For example, when the lowerportion 110 a of the rim 110 is held by the driver, the driver's hand isplaced in proximity to the sensor portion 130 a of the capacitive sensor130 and within the detection area 150 a, thus allowing the driver's handto be detected. Further, when the lower portion 110 b of the rim 110 isheld by the driver, the driver's hand is placed in proximity to thesensor portion 130 b of the capacitive sensor 130 and within thedetection area 150 b, thus allowing the driver's hand to be detected.

Further, while the driver is driving the vehicle, the driver's hand maycontact a connecting portion between the spoke 120 and the rim 110 orcontact the vicinity of the connecting portion. For example, if thedriver's hand contacts the connecting portion 120 a of the spoke 120 orcontacts the vicinity of the connecting portion 120 a, the driver's handis in proximity to the sensor portion 130 e of the capacitive sensor 130and within the detection area 150 a or the detection area 150 b, thusallowing the driver's hand to be detected by the controller 160.Further, if the driver's hand, approaching the sensor portion 130 e ofthe capacitive sensor 130, is placed in proximity to the connectingportion 120 a side of the sensor portion 130 a or the connecting portion120 a side of the sensor portion 130 b, the driver's hand enters thedetection area 150 a or the detection area 150 b, thus allowing thedriver's hand to be detected by the controller 160.

Further, if the driver's hand contacts the connecting portion 120 b ofthe spoke 120 or contacts the vicinity of the connecting portion 120 b,the driver's hand is placed in proximity to the sensor portion 130 f orthe sensor portion 130 c and within the detection area 150 c, thusallowing the driver's hand to be detected by the controller 160. If thedriver's hand contacts the connecting portion 120 c of the spoke 120 orcontacts the vicinity of the connecting portion 120 c, the driver's handis placed in proximity to the sensor portion 130 g or the sensor portion130 d and within the detection area 150 c, thus allowing the controller160 to detect the driver's hand.

(Steering Wheel Sensor and Steering Wheel According to SecondEmbodiment)

In the following, a steering wheel sensor and a steering wheel accordingto a second embodiment will be described with reference to FIG. 8 andFIG. 9. In the second embodiment, the same elements as those of thefirst embodiment are denoted by the same reference numerals.

In a configuration according to the second embodiment, it is assumedthat the drive mainly holds an upper portion 110 c of the annular rim110 illustrated in FIG. 8 while the driver is driving the vehicle.

In the second embodiment, as illustrated in FIG. 8, the steering wheel100 includes the annular rim 110, the spoke 120 that is connected to theinner side of the rim 110, and the steering wheel sensor 102 that isprovided on the spoke 120. The connecting portions 120 a, 120 b, and 120c connect the spoke 120 to the rim 110.

The steering wheel sensor 102 includes the capacitive sensor 130(corresponding to the “electrode” recited in the claims). The capacitivesensor 130 is provided along the edge portions, facing the innerperipheral surface of the rim 110, of the spoke 120, and can becapacitively coupled to an object (“operation body”) to be detected andhaving a capacitance. Further, the steering wheel sensor 102 includes acapacitive sensor 131 (corresponding to the “electrode” recited in theclaims). The capacitive sensor 131 is provided along the edge portion,facing the inner peripheral surface of the rim 110, of the spoke 120,and can be capacitively coupled to the operation body having acapacitance. Further, the steering wheel sensor 102 includes thecontroller 160 that is electrically connected to the capacitive sensor130 and to the capacitive sensor 131.

The capacitive sensor 130 includes the sensor portions 130 a and 130 b(corresponding to the “fragments” recited in the claims). The sensorportions 130 a and 130 b are provided along the lower edge portions 121a and 121 b, facing the inner peripheral surface of the rim 110, of thespoke 120. The capacitive sensor 130 further includes the sensor portion130 c (corresponding to the “fragment” recited in the claims) and thesensor portion 130 d (corresponding to the “fragment” recited in theclaims). The sensor portion 130 c and the sensor portion 130 d areprovided along parts of the upper edge portion 121 c of the spoke 120.The sensor portion 130 c is located closer to the connecting portion 120b, and the sensor portion 130 d is located closer to the connectingportion 120 c.

The capacitive sensor 130 is formed of one conductive wire. Thecapacitive sensor 130 includes the sensor portion 130 c, the sensorportion 130 f, the sensor portion 130 a, the sensor portion 130 e, thesensor portion 130 b, the sensor portion 130 g, and the sensor portion130 d, which are connected in this order. The sensor portions of thecapacitive sensor 130 have different electrical resistance values basedon the distances from the rim 110.

The capacitive sensor 131 is provided along a part of the upper edgeportion 121 c, facing the inner peripheral surface of the rim 110.Further, the capacitive sensor 131 is located at a position where thesensor portion 130 c and the sensor portion 130 d of the capacitivesensor 130 are not provided.

In the second embodiment, the capacitive sensor 131 is provided alongthe part of the upper edge portion 121 c so as not to overlap thecapacitive sensor 130. However, the capacitive sensor 131 may beprovided so as to overlap the capacitive sensor 130 to the extent thatmisdetection does not occur.

As illustrated in FIG. 9, the capacitive sensor 130 and the capacitivesensor 131 are connected in parallel to the controller 160.

The capacitive sensor 131 has an electrical resistance value differentfrom those of the capacitive sensor 130. As illustrated in FIG. 8, thecapacitive sensor 131 is provided along the part of the upper edgeportion 121 c of the spoke 120, and is located away from the connectingportion 120 b and the connecting portion 120 c. In other words, thecapacitive sensor 131 is provided along the center part of the upperedge portion 121 c of the spoke 120. If the spoke 120 has a typicalshape, such as a T-shape, the distance between the capacitive sensor 131and the rim 110 is greater than the distance between the capacitivesensor 130 and the rim 110. Therefore, the detection sensitivity of thecapacitive sensor 131 is preferably set to be higher than the detectionsensitivity of the capacitive sensor 130.

If the operation body contacts or is placed in proximity to the rim 110,the capacitance of the capacitive sensor 130 or the capacitance of thecapacitive sensor 131 changes. When there is a change in the capacitanceof the capacitive sensor 130 or in the capacitance of the capacitivesensor 131, the controller 160 detects the change, and generates adetection signal. Based on the detection signal, the controller 160 oran external device illustrated in FIG. 9 determines whether theoperation body contacts or approaches the rim 110. At this time, thecontroller 160 determines whether the operation body contacts or isplaced in proximity to the rim 110 by comparing the detection signal tothresholds that are set based on the distances between the rim 110 andthe capacitive sensors 130 and 131.

As illustrated in FIG. 8, detection areas 150 a, 150 b, 150 c, and 150 dare set in the surroundings of the rim 110, a space between the rim 110and the capacitive sensor 130, and a space between the rim 110 and thecapacitive sensor 131.

If the operation body is located with the detection area 150 a, thedetection area 150 b, the detection area 150 c, or the detection area150 d, the capacitance of the capacitive sensor 130 or capacitance ofthe capacitive sensor 131 changes. The controller 160 detects the changein the capacitance of the capacitive sensor 130 or capacitance of thecapacitive sensor 131, and generates a detection signal.

The controller 160 or the external device illustrated in FIG. 9determines whether the operation body contacts or is placed in proximityto the rim 110 based on the detection signal.

Although the embodiments have been described in detail above, thepresent invention is not limited to the particulars of theabove-described embodiments. Various modifications and variations may bemade without departing from the scope of the present invention.

What is claimed is:
 1. A sensor device of a capacitive type for use witha steering wheel, the steering wheel including a rim and a spoke that isconnected to an inner side of the rim, and the sensor device beingprovided on the spoke, the sensor device comprising: an electrodeconfigured to be capacitively coupleable to an object to be detected;and a controller configured to detect a change in capacitance of theelectrode, and determine whether the object is in proximity to the rimor the spoke based on the change in the capacitance of the electrode,the change in the capacitance of the electrode occurring in response tothe object being in proximity to the rim or the spoke.
 2. The sensordevice according to claim 1, wherein the electrode is to be providedalong edge portions of the spoke, the edge portions facing the rim. 3.The sensor device according to claim 2, wherein the electrode is to beprovided along connecting portions of the spoke that connect the spoketo the rim.
 4. The sensor device according to claim 3, wherein an outerperiphery of the spoke includes the edge portions and the connectingportions, and the electrode extends continuously along the outerperiphery of the spoke.
 5. The sensor device according to claim 2,wherein the electrode includes one or more electrical conductors.
 6. Thesensor device according to claim 1, wherein the electrode includes aplurality of fragments having different electrical resistance valuesbased on distances from the rim.
 7. The sensor device according to claim1, wherein the controller is configured to make the determination bycomparing a signal from the electrode to a threshold, the thresholdbeing set based on a distance between the rim and the electrode.
 8. Thesensor device according to claim 1, wherein a detection area extendsalong a plane that includes the rim.
 9. A steering wheel comprising, thesensor device according to claim
 1. 10. A steering wheel comprising: thesensor device according to claim 1; and a heater provided inside the rimand configured to heat the rim.